<!DOCTYPE html>
<html class="reftest-wait">
<title>Tests anchor-positioned element paint order in composited scrolling</title>
<link rel="help" href="https://drafts4.csswg.org/css-anchor-position-1/#scroll">
<link rel="author" href="mailto:xiaochengh@chromium.org">
<link rel="match" href="reference/anchor-scroll-composited-scrolling-006-ref.html">
<style>
body {
  margin: 0;
}
#scroller {
  width: 200px;
  height: 100px;
  overflow: scroll;
  will-change: scroll-position;
}
#spacer {
  height: 400px;
}
#anchor {
  width: 100px;
  height: 100px;
  anchor-name: --a;
}
#target {
  position: absolute;
  width: 100px;
  height: 100px;
  background: red;
  left: 0;
  bottom: anchor(top);
  position-anchor: --a;
}
#overlap {
  position: absolute;
  width: 100px;
  height: 100px;
  top: 150px;
  left: 0;
  z-index: 100;
  background: green;
}
</style>

<div id="overlap"></div>
<div id="scroller">
  <div id="spacer"></div>
  <div id="anchor"></div>
</div>
<div id="target"></div>

<script type="module">
function raf() { return new Promise(resolve => requestAnimationFrame(resolve)); }

await raf();
await raf();
scroller.scrollTop = 150;

document.documentElement.classList.remove('reftest-wait');
</script>
</html>
